How many solutions does the equation −2a + 2a + 7 = 8 have? one two none infinitely many.
i'm pretty sure it's only 1 but just want to make sure.

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label?